Windows Impair Defense Define Win Defender Threat Action
The following analytic detects modifications to the Windows Defender ThreatSeverityDefaultAction registry setting. It leverages data from the Endpoint.Registry datamodel to identify changes in registry values that…
Description
The following analytic detects modifications to the Windows Defender ThreatSeverityDefaultAction registry setting. It leverages data from the Endpoint.Registry datamodel to identify changes in registry values that define how Windows Defender responds to threats. This activity is significant because altering these settings can impair the system's defense mechanisms, potentially allowing threats to go unaddressed. If confirmed malicious, this could enable attackers to bypass antivirus protections, leading to persistent threats and increased risk of data compromise or further system exploitation.
Detection logic
Detection requirements
- Platform
- ContainersESXiIaaSLinuxmacOSNetwork DevicesWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- sysmon_eventid_13
Known benign triggers
- It is unusual to turn this feature off a Windows system since it is a default security control, although it is not rare for some policies to disable it. Although no false positives have been identified, use the provided filter macro to tune the search.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| github.com/undergroundwires/privacy.sexy | 22 |
| x.com/malmoeb/status/1742604217989415386?s=20 | 22 |
From the source
- At source
- Open at source
- Upstream identifier
- 7215831c-8252-4ae3-8d43-db588e82f952
- Tagged by the source as
- Windows Defense Evasion TacticsWindows Registry AbuseEndpointendpointSplunk CloudSplunk EnterpriseSplunk Enterprise Securityendpoint
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Aug 26, 2026
- Version
- 1